Carbon-impregnated body electrode

ABSTRACT

A carbon-impregnated plastic or metallic male electrode is disposed within a body contacting adhesive coated web, the electrode being secured to the skin of a patient by the adhesive for the purpose of conducting electrical currents to and from the body of the patient. A conductive paste or jelly may be used to enhance conduction through the junction of the electrode with the body, if desired.

United States Patent [72] Inventor Lucas H. Moe, Jr.

Andover, Conn. [21] Appl. No. 785,577 [22] Filed Dec. 20,1968 [45] Patented Mar. 2, 1971 [73] Assignee United Aircraft Corporation East Hartford, Conn.

[54] CARBON-IMPREGNATED BODY ELECTRODE 1 Claim, 4 Drawing Figs. [52] US. Cl l28/2.06, 128/417,128/418 [51] lnt.CI A61b 5/04, A6'1n 1/02 (50] Field of Search 128/416- 4l8, 2.06, (pick-up digest); 252/511 [56] References Cited UNITED STATES PATENTS 2,065,295 12/ 1936 Sullivan 128/416X 2,081,517 5/1937 Van Hoffen 128/417UX Dobes 1 Primary ExaminerRichard A. Gaudet Assistant Examiner-Kyle L. Howell Att0rneyMelvin Pearson Williams ABSTRACT: A carbon-impregnated plastic or metallic male electrode is disposed within a body contacting adhesive coated web, the electrode being secured to the skin of a patient by the adhesive for the purpose of conducting electrical currents to and from the body of the patient. A conductive paste or jelly may be used to enhance conduction through the junction of the electrode with the body, if desired.

1. Field of Invention This invention relates to body electrodes, and more particulariy to an improved one-piece body electrode.

2. Description of the Prior Art It is well known in the electromedical art that electrical currents may be passed to and from the body of a patient through an electrode secured to the skin of a patient by a piece of adhesive tape or the like. In order to enhance conduction of the joint between the electrode and the skin, it has been common to utilize an electrically conductive paste or jelly which is applied to the skin at the point where the electrode will make contact, before securing the electrode tothe body of the patient. An electrode of this type is described in US. Pat. No. 3,085,557 to Berman et al.

A great deal of attention has been paid recently to the irritating effects which have heretofore been believed due solely to the content of the electrically conductive paste or jelly. Although the irritation varies from patient to patient, nearly all patients express skin irritation whenever the jelly is left on the skin for periods in excess of 24 hours. As described in the aforementioned Berman et al. patent, it is the function of these electrodes in many cases to allow a patient to perform normally at his home and/or at work while his heart wave is being monitored through telemetry equipment in the office of the physician. Thus, there is frequently a need to have the patient wear the body contact electrode for some period of time.

It has been observed that there is a discoloration of the electrically conductive paste which occurs sometime after the application of the paste and the electrode to the patient. This is believed to be due, at least in part, to the fact that body electrodes of the prior art are usually comprised of metals which can react electrolytically with the electrically conductive paste. For instance, one electrode known to the prior art comprises a nickel coated copper electrode which is formed by crimping, during the process of which a portion of the nickel is removed from the surface of the copper. Although this results only in minute areas of copper being exposed, the conductive jelly can nonetheless react therewith, particularly in the presence of an electric current. it is believed that the galvanic action between the various metals and the conductive paste forms compounds which in turn irritate the skin. This suggests that rather than the jelly itself being an irritant, it is the combination of the electrodes with the jelly in the presence of an electric current which'causes skin irritation.

SUMMARY OF THE INVENTION An object of the present invention is to provide a body electrode which is simple and inexpensive to make, and which avoids the generation of skin irritants as a result of contact with an electrically conductive paste orjelly in the presence of an electrical current.

According to the present invention, a body electrode comprises a single male portion composed of a relatively inert material such as phenolic resin, carbon-impregnated fluorocarbon, or a relatively inactive metal in combination with a single adhesive member for securing the electrode to the skin of a patient.

By eliminating the use of crimped, plated metal in the electrode which is applied to the body of the wearer, galvanic reactions with electrically conductive pastes are avoided, thus minimizing the chances of generating skin irritants in the presence of an electric current. Furthermore, the simplicity of the construction permits mass production at very low cost, thus enhancing the value of the electrode as a disposable adjunctive modality in monitoring heart waves as well as in other electromedical processes known to the art. The electrode, when made in the fashion of a male portion of a snap fastener, may be utilized with female snap conductors applied to the leads of electrical monitoring equipment, in the same fashion as electrodes heretofore available.

The foregoing and other objects, features and advantages of the present invention will become more apparent in the light of the following detailed description of a preferred embodiment thereof, as illustrated in the accompanying drawing.

BRlEF DESCRIPTION OF THE DRAWING FIG. 1 is a cross section of a body electrode in accordance with the present invention, illustrating protective peal off layers utilized during shipment and handling of the electrode;

FIG. 2 is a plan view of an adhesive patch which may be used with the embodiments herein, including a circular hole cut in the center and square overall configuration;

FIG. 3 is a plan view of an adhesive patch which may be utilized with the embodiments herein, including an overall configuration of generally circular symmetry, and crossed slots therein to permit the passage of the electrode therethrough; and

FIG. 4 is a cross section of the electrode when applied to a body for utilization thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, the body electrode in accordance with the present invention comprises a principal portion 10 which is composed of a plastic such as nylon, Teflon or silicone rubber, impregnated with electrically conductive material, such as carbon or graphite. However, a particularly advantageous composition is polytetrafluoroethylene, or Teflon impregnated with graphite which is marketed under the trade name Formulation LF-2l9 by the Polymer Corporation, Reading, Pa, (the precise composition of which is not revealed by the maker to the general public).

A second preferred material is a moldable, conductive phenolic resin marketed under the identification of No. 0575 by Beckwith Carbon Corporation; Van Nuys, Cal.; the composition of this material is unknown to the public. Alternatively, it may comprise nickel or silver plated copper, or a solid conductive metal. The main electrode piece 10 has a configuration which gives it a wide contact surface l2 for contact with the skin, and a neck portion 14 on which a crown portion 16 is disposed. This permits it to act as the male portion of a snap fastener, in the same fashion as that described in said Berman et al. patent, as is well known in the art. Alternatively, the neck portion 14 may be straightened, thus avoiding need for a two-piece mold, if desired. An adhesive webbing or patch 18 is fitted around the neck portion M of the electrode l0 so as to permit the electrode 10 to be readily secured to the skin of a patient. The adhesive patch 18 may take the configuration of the patch lltla shown in plan view in H6. 2, or it may take the configuration of the patch 18b shown in FIG. 3. Thus, it may have an overall configuration which is either square or round or in any other suitable shape, and it may be provided with a hole 20 to permit passage of the neck 14 and crown to therethrough, or it may be provided with crossed cuts 22 (which may be single dimension cuts, or slits or slots). Obviously, other suitable accommodations may be formed in the patch l8 so as to permit passage of the neck and crown of the electrode 10 therethrough.

Although the adhesive patch 18 may have adhesive applied throughout the entire bottom edge 24 thereof, it is not necessary that adhesive actually contact the electrode 10. That is, an area commensurate with the area of the patch 18 which contacts the electrode 10 may have no adhesive applied thereto, if desired to suit any implementation of the present invention. This is so because the adhesive in any case will readily hold the electrode to the skin of the wearer, and the combination of the adhesive with a pair of pealoff protective layers 26, 28 will hold the various parts together during shipment and handling. The pealoff portions 26, 28 may be of any conventional form, such as that illustrated in the Berrnan et al. patent.

The body electrode in accordance with the present invention is applied to the skin of a patient in a conventional manner as illustrated in FIG. 4. Therein, a small amount of conductive jelly or paste 3ft may be applied to a spot on the skin 32 of the wearer where the electrode is to be positioned. Thereafter, the pealoff protective layers 26, 28 (FIG. 1) are removed so that the electrode may be applied directly to the area covered with the conductive paste 30. The adhesive patch i8 is then pressed to the skin so as to tightly seal the conductive jelly or paste within the confines of the adhesive bond, and to press the surface 12 of the electrode in electrically conductive relation to the paste 30 at the point of contact with the skin. The nature of the contact made is described more fully in said Berman et al. patent.

It can be seen that an electrode in accordance with the present invention avoids the use of any electrolytically active metallic parts in contact with the skin, or in contact with the conductive paste or jelly. Thus, electrolysis is avoided, whereby the possibility of generating skin irritants is minimized. Also, it is obvious that a body electrode in accordance with the present invention can be manufactured at a very low cost since only two parts are involved, and the electrode portion 10 may be molded in accordance with molding techniques well known in the art.

Although the invention has been shown and described with respect to preferred embodiments thereof, it should be understood by those skilled in the art that the foregoing and various other changes and omissions in the form and detail thereof may be made therein without departing from the spirit and the scope of the invention.

1 claim:

1. A body electrode consisting solely of:

a one-piece electrode portion consisting of carbon-impregnated plastic material selected from the group consisting of polytetrafluoroethylene and phenolic resin, and having an enlarged skin contact area, and neck and crown sections forming a male snap fastener; and

an adhesive webbing having adhesive disposed on one side thereof and having an opening therethrough, said neck and crown sections protruding through said opening in said webbing, said adhesive contacting said electrode portion, said web extending beyond said body portion for securing said electrode to the skin of the body. 

